The present invention relates to novel substituted thiophenesulfonamide compounds, salts thereof, herbicides containing the same, and a process for preparing the same. The thiophenesulfonamide compounds of the present invention substituted by an ethenyl or propenyl group having all hydrogen atoms replaced by chlorine atoms and/or fluorine atoms, and the salts of such thiophenesulfonamide compounds are both novel. U.S. Pat. No. 4,398,939 and Japanese Unexamined Published Application No. 24383/82 show thiophenesulfonamide compounds substituted by an alkenyl group having 3 carbon atoms (propenyl group). These compounds have different chemical structures from the compounds of the present invention in that in the latter compounds, i.e., all hydrogen atoms are replaced by chlorine atoms and/or fluorine atoms.